DSS-E.05.02 — Oxidation Darkening of Films

Oxidation darkening of films is an appearance change on glass caused by oxidative aging of organic surface residues (maintenance detergents/additives, HVAC/kitchen aerosols, traffic-related organics) and/or particulate entrainment (soot/oxyde fines) within those films. It presents as a neutral grey to brown dark veil, often patchy and aligned with wipe paths or airflow cones, with wetting anomalies at boundaries. Classification is appearance-only per VIS (method-agnostic). Inspect after Non-Invasive Reveal under VIS lighting/geometry; record surface numbering and worked-surface status.

• Grey→brown dark cast, stronger on high-UV / ozone / pollutant exposures or near traffic/exhaust.
• Patch maps following squeegee strokes, spray cones, return-air vectors, or range-hood plumes.
• Boundary edges show bead/sheet contrast when misted due to altered surface energy.

Surface-catch class (MSRT)

• Generally SC-0 (aged film on top).
• Local SC-1 where long dwell entrained grit or led to incipient substrate micro-texture; SC-2 suggests misclassification-evaluate M.02 abrasion fields or Ch.03.03 mineral etching if matte persists after true film lift.
• Perform one light, non-marring pass on a small revealed test patch (substrate). Use polymer stylus if a functional coating is suspected. MSRT supports classification only.

Visual signature

• Neutral-to-warm dark veil, often non-uniform; no chip-flank sparkle, no discrete pits.
• Wipe/air-path geometry is common; edges appear harder/darker in raking.

Viewing / lighting

• Evaluate clean & dry at 12 / 36 / 72 in, normal and oblique sweep (~60°-120°); use raking to reveal film thickness and edge outlines. Record distances/angles in-frame.

Location / access

• Record pane ID and surface numbering (#1-#4; laminate-internal). Seen on outboard (#1) near roadways/exhausts and inboard (#4) near kitchens/HVAC. Between-pane detection on #2/#3 via parallax → CAT-5 by location.

Mechanism cue (context)

• History of detergent/additive stacking, infrequent true rinsing, HVAC carryover, cooking aerosols, diesel corridors; darker accumulation on windward or airflow sides.

Assign CAT by visibility at acceptance geometry and MSRT after a true film-lift test. Depth values are indicative-field measurement not required.

• CAT-1 (Benign / non-relief): Thin dark veil; SC-0; angle/raking visible; clears fully on reveal patch. Indicative relief: 0-10 μm (optical film only).
• CAT-2 (Light): Persistent dark cast post-reveal with localized SC-1 (incipient substrate change or grit-imprinted micro-texture); limited standard-view impact. Indicative relief: ~10-40 μm.
• CAT-3 (Moderate): Wide-area darkening legible at standard distance, scattered SC-1; indicates long dwell/re-application cycles and oxidative aging. Indicative relief: ~40-120 μm.
• Reclassify when: Amber/yellow hue dominates tied to UV → consider E.05.01 UV-browning; oily neutral film with strong wetting anomalies → R.04.03 HVAC oil / R.04.04 kitchen grease; white/grey crystalline rims/etch → Ch.03 mineral system; linear swirls/webs → M.02 abrasion fields.
• CAT-5 (by condition/location): Between-pane/inaccessible by parallax, integrity indicators, or confirmed functional-coating loss on the surface to be worked → CAT-5.

CAT is appearance-based; acceptance is separate under VIS-A at 12/36/72 in. Do not abrade to “force” a response during classification.

• vs. Soot/particulate film (E.01.03): Soot is dry/transferable and often black; oxidation-darkened films are bound, show wipe geometry, and can be brown/grey.
• vs. UV-browning (E.05.01): UV-browning trends amber/yellow; oxidation darkening trends neutral grey/brown, often pollutant-associated.
• vs. Nicotine/tar (R.04.05): Nicotine is amber/brown with odor and interior airflow mapping; oxidation darkening commonly includes exterior pollutant capture signatures.
• vs. Coating anomalies (Co-family): Coating issues are planar/patchy on designated faces and are independent of wipe/airflow geometry; films respond to film-lift testing.

• Photo set (VIS): 12 / 36 / 72 in, normal + oblique; raking macros of film edges, color/density variations, and wetting anomalies; context frames of traffic/exhaust/HVAC/kitchen zones. Record distance/angle in-frame.
• MSRT result (substrate): After a small reveal test patch and true film-lift, perform one light, non-marring pass; record SC-class (SC-0/SC-1/SC-2).
• Forms: Pane ID; product family & surface numbering; worked surface Y/N; functional coating present on worked surface? (Y/N/Unknown); reveal status; lighting/time; geometry checklist; photos attached.
• Acceptance split: Post-restoration acceptance per VIS-A §6; classification ≠ acceptance. Coated-face appearance rules apply per VIS §6.2.e when the worked surface is a factory functional coating.

• E.05.02 Oxidation Darkening of Films - Grey→brown aged organic film with wipe/airflow geometry on surface #___; post-reveal test patch shows [SC-0 film / SC-1 localized]; visible at [12/36/72 in] under VIS geometry. Morphology: oxidized dark veil, wetting anomalies, no chip-flank sparkle, no pits. Classification: CAT-[1/2/3] by visibility and SC-class; reclassify to E.05.01 (UV-browning), R.04.03/04 (oily films), Ch.03 (mineral), or M.02 (abrasion) as indicated; CAT-5 if between-pane or coating-side loss on the surface to be worked. Forms + photo set attached; acceptance per VIS-A §6.

⭐ DSS-V

Damage Specification Standards 2026

DSS-V Vandalism/Intentional Surface Modification

Draft v1.0

V.01 Abrasive & Mechanical

• V.01.01 Sandblast/abrasive blast etch (uniform frosted field)
• V.01.02 Scribed/engraved tool marks

V.02 Chemical

• V.02.01 Acid‐marker tagging (HF‐bearing)
• V.02.02 Etch‐cream patterning (consumer etchant traces)

V.03 Coatings & Paints

• V.03.01 Spray paint/marker coatings
• V.03.02 Sticker/poster adhesive campaigns (mass adhesive residue)